Unclaimed Blue Suitcase

Tang Xing opened a community inn. He hated dealing with unclaimed parcels. Until that blue suitcase sat in the corner for 43 days. Neither the sender nor the recipient can be reached by phone, and no one recognizes the address. What's even weirder is that it rings the phone alarm at 9:07 every night. On the 43rd day, there was an additional recording after the ringtone: "Don't forget to go home." Tang Xing wanted to hand it over as required, but found an old mobile phone, three blank postcards and a handwritten recipe book in the box. When the phone lights up, the screen reads: "On the 44th day, if no one comes, give him the recipe."